 I have AT&T and AT&T does fiber to the home. This is not like cable at all as there is no modem. There is a router, but you cannot replace the AT&T router easily. In my case, the fiber goes to an ONT, optical network terminal. This converts the optical stuff to Ethernet and then that goes to the AT&T router. The issue is that the router logs onto the AT&T network with an encrypted handshake that includes a certificate.